Reciprocating-tool mechanism.



w. F. TROTTER.

RECIPROGATING TOOL NIECHANISIVI.

APPLICATION FILED SEPT.20, 1907- RENEWED JUNE I7. I9I5.

Patented J an. 18, 1916.

4 SHEETS-SHEET I.

Mv L III f www.

'I ILIIIIII -IUUIIII Wi h1 woes W. FL TROTTER.'

RECIPRCATING TOOL MECHANISM. APPLICATION FILED sEPT.20, 1907. IIEIIEWED IuIIE I7, I9Is.

1,168,834. Patented Jan.18,1916.

4 SHEETS-SHFET` 2.

THB COLUMBIA PLAHDGRAPH co., WASHINGTON, u. c

w. F. TROTTER.

RECIPROCATING TOOL MECHANISM.

APPLICATION FILED SEPT-20,1907. RENEWED JUNE 17,-1915.

1,168,834. Patented Jan. 18, 1916 4 SHEETS-SHEET 3.

@Hoz nu? W. F. TROTTER` RECIPROCTING TUOI. IVIECHANISMt APPLICATION FILED SEPLZO, 1907. IIEIIEwED IuIIE- I7, I9I5.

l, 168,834., Patented Jan. 18, 1916.

4 SHEETS-SHEET 4.

@V tu uns THE COLUMBIA vuNoGIzAPH co.. WASHINGTQN. D'. C.

WALTER I F. TROTTEB., 0F CHARLESTON,

sare are weer vIneInIr-i, assis-noa, :BY MnsNn 0F OHIO.

RECIPROCATINGr-TOOL MECHANISM.

Specification of Letters Patent.

Patented aan. is, raie.

Application filed September 20, 1907, Serial No. 393,835. Renewed June 17, 1915. Serial No. 34,739.

To all whom t may concern:

Be it known that l, VVAL'rnn F. Tno'rrnn, a citizen of the United .States, residingat Charleston, in the county of lianawha Vand State of i/Vest Virginia, have invented certain new and useful improvements in Reciprocating-Tool Mechanism, of which the following is a specification, reference being had therein to the accompanying drawing.

This invention relates to improvements in tools of the class in which each has, as its principal operative part, a. reciprocating body by which blows are imparted to the material which is being operated on.

As an example of the mechanisms which can be constructed with the improvements, a reciprocating drill is shown herein adapted for use inthe cutting of rock, coal and similar materials.

Figure 1 is a longitudinal section of a rock-drill or coal-drill embodying the improvements. Fig. 2 is a top plan view partly in section. Fig. 3 is an enlarged side elevation of part of the operating mechanism. Fig. 4 is an enlarged perspective view of the eccentric shifting member. Fig. 5 is an enlarged sectional view of the worm wheel. Figs. 6, 7, 8 and 9 are enlarged sectional views, more or less diagrammaticin character, illustrating the diiferent positions of the parts when in operation.

The tool selected for illustration in the drawings is of they class mounted upon wheels and provided with handles so that it can be readily manipulated by the operator.

The wheels are indicated by l3 2.

3 indicates a rod serving as a carrier for the tool proper, such as a drill bit and stem. At the rear end the rod 3 is secured to the piston 5 which is iitted in the chamber (i of a cylinder' 7 is closed by a head 9 which may be provided with a gland and stuffing box, if desired. In

the present case the head, as shown, is'provided with a sleeve extension 4 to guide the tool rod 3.

rfhe upper part ofthe wall of the cylinder is shown at 11.

At 12 and 13 are respectively the front port and the rear port in the cylinder walls. Adjacent to the cylinder chamber 6 there is a. valve chamber 32 having ports 15 and 1G in its walls, the former connecting by a duct 14 with the rear cylinder port 13, and the r1`he front end of the cylinderV latter by a short duct with the cylinder port 12. y

17 and 18 indicate respectively the rear feed port and the front feed port yof the valve chamber 32. In this chamber there are two valves 29 and 30, the former adapted to open and to close the ports 15 and 17 and the latter to open and to close the ports at 16 and 18. The valves 29 and 30 are secured to a valve operating rod 31 which extends through the metal at 31a, and outside thereof is connected to the valve actuating gear to be described.

19 indicates a compression chamber within a cylinder 20. In this chamber is fitted the pump piston 22. Y

23 and 24 are ports in the walls of the pump cylinder or compression chamber, these communicating with each other through the duct 25.

26 and 27 are similar ports at the other endy of the pump cylinder and communicating with each other through a duct 28.

The pump piston 22 is connected to the rod 36 which passes through the end wall 36 provided, if necessary, with a stuffingbox or gland and connected to the crosshead 37 in the guide 35. To the cross-head is pivoted the pitman 38 which at the rear end is connected to the crank 39 on the main shaft 40, the latter being mounted in suitable bearings carried by the frame. f

On the shaft 40 there is an eccentric 41 connected by a strap 41a and a link 42 to the cranlr 45 on the shaft 44. The shaft 44 carries cranl; 46 which is connected to the valve rod 31. Means are provided for varying the throw and angular relation of the eccentric while the machine is in operation,

in the manner and for the purpose hereinafter set forth. The shaft 40 is rotated by the worm wheel 47 with which engages the worm 48 mounted on the armature shaft of the electric' motor 49, the latter being shown conventionally in the drawing. The worm wheel 47 is rigidly secured to shaft 40 by means of the boss 472L and the screws 47h, as indicated in F ig. 5.

lFhe eccentric disk-41 is movably mounted upon the face of the gear 47, being retained in position by the screw bolts 57-58 passed through the slots 59-60 in said gear. A large, elongated aperture or slot 41 Vis formed in the eccentric disk and this slot receives an inner eccentric 61 which is ro- Ico .end 62 of the sleeve 6 2u is a pin carried by sleeve 62 and engaging the spiral groove 61'. When the sleeve 62 is moved longitudinally, the pin 62a by engage` ment with the spiral groove-causes the eccentric 61 to turn in respect to shaft 110 and so to shift the eccentric proper 41, increasing or decreasing its throw according as the sleeve is moved outwardly or inwardly. he movement of the eccentric fil with respect` .to the shaft is determined by the slots 59-60 in which the screw bolts 5'7-58 are slidably mounted, andk these slots are so shaped that the eccentric all is moved angularly with respect to the crank 39 at the same time that it is moved laterally across the shaft. A spring locking finger 65 mounted on handle 53 and notched to engage the shifting lever 63 serves to hold sleeve 62 in adjusted position. v n

The metal which provides the walls for theftool cylinder 7, the valve chamber 32 and the compression chamber 19, together with the guide at 35, can be in one piece consti` tuting aframe for supporting the movable parts, and in the present instance` the casting is` also provided with arms having depending brackets 50', the same carrying Athe shafts 40 and 14, respectively, and with trunnions 51, 52 upon which are mounted the Wheels 1 and 2. The arms 50 also carry the handles 53. v

At 54 there is a valve in the head` plate of the pump chamber mounted in a seat thimble 55 inserted into the plate. The valve is normally held in place by the spring at 56.

VThis .valve acts to permit the entering of bodies of air from time totime tothe in yterior'chambers if the volume of air therein is decreased, through leakage or otherwise,

vto such an extent as to lower the pressure below the desired limit.

A mechanism having parts constructed and related in the way described can be used as follows: By preference a volume of air is preliminarily stored in the interior chambers such as to furnish a pressure considerably above that of the atmospherc,and in* tericr pressure of forty pounds being pre-v ferred. If now the motor be set in operation the action of the parts will be as follows: Assuming that the movements com'- lmence when the parts are 'in the positions shown in Fig. 6, the pump piston 22 starts forward, the valve pistons 29 andBO at the same instant commencing` to move rearward. The port-s and ducts at 17, 18 are open and also those at 15, 16 and 12, 18. There is at this time an equalization of pressure, in both parts of theA circuit, that is, on both sides of the pump piston 22, this piston, at the instant referred to, leaving openv both the ports 23, 2&1- and their connecting duct 25. As soon as the` piston 22 starts forward, however, the port 24 is closed and a relative increase of pressure is produced on the front side of the piston. lThe air in front is forced across the valve chamber 32 into the forward end of the chamber 6, and the-piston 5 and the tool move backward. lWhen the pump piston reaches the center of its stroke forward, the valve pistons 29 and 30 having completed their rearward stroke and again started forward are in the position shown in Fig. 7, while` the piston 5 isstill moving toward the rear, as indicated in said figure. Simultaneously Ywith the increase of pressure on the front sides of the pistons 22, there is a decrease in pressure on their rear sides which assists in drawing the piston 5 backward. At` the time the pump piston 22 reaches the forwardV end of its stroke, as shown in Fig. S, the tool-piston has reached the rear end of its vchamber 6, and the valves `29, 30 cle-se the ports 17, 15 and 18, 16. r A

small body of air istherefore cut ofr1 from escape from thcrear end of the tool cylinder '7 and the tool-piston is cushioned. While the piston is in the forward end of lthe cylinder, as shown inl Fig. 8, the-pressure on the pump 'chamber is equalized on vboth sides ofthe piston through the ports 26, 27 andthe bypass 28. By the time the pump piston has reached the central part, or points a little beyond the central part of its chamber, on its returnfstroke, the valves 29, 30 are reversed and open the portways at 17, 15, 13 and 18, 16, 12, (see Fig. 9); At this instant a large volume of air in the rear end of the pump chamber is under high compression and rushesrapidly to the rear end of the ytool cylinder behind the tool-piston. This resultsin driving this piston and the tool forward with a powerful blow. The forward motion continues until the several parts havel again reached the position indicated in Fig. 6. At this time there is a suiiicient'volume of air in the forward part of the tool cylinder to cushion the piston, and tool on theforward stroke. f

I prefer to so construct and proportion the parts that, `if the initial interna-l vpressure throughout the circuit is forty pounds,the pressure behind the pump piston at the instant the valves 29 and 30 are opened shall be about v pounds. Just after the piston 22 reverses at the forward end of its stroke i ,isses/i a3 and closes port 26 there Will be considerable drop in pressure on its front side and in case of leakage or loss of air from the circuit said pressure may fall beloW that of the atmosphere. When this occurs the valve 54 yields inward under the higher external pressure and snl'licient 'air is allowed t0 enter to restore the predetermined pressure. Obviously the mean normal pressure maintained in the closed circuit may be varied by adjusting the tension of spring 56. l/Vhen the pump piston is moving forward to eiiect the backward movement or" the tool-piston 5, the ports across the valve chamber are left open during the entire stroke of the pump piston and consequently the air on the forward side of the tool-piston: will carry it backward Without sudden or quick movements, That is to say, the cycle of movement of the tool-piston comprises a relatively slow, uniform movement backward and a sudden, quick movement for- Ward. The time at which the forward movement oi' the tool and its piston commences can be varied by varying the movement of the valves through the eccentric-adjusting devices above referred to. By reason of the combined angular and lateral movement given to the eccentric by the shifting mechanism, the point in the cycle or operations at which valves 259-30 close remains unchanged, while the point at which they open varies through a` considerable range.

I prefer, under ordinary circumstances, to have the valve 29 open the ports at 17 and 15 at about the half-Way point of the travel of the piston Q2, and under such adjustment the tool-piston makes a whole stroke while thepump piston is making a half stroke. But it will be understood that the opening of the valves may be timed at Will by the operator by means of the controllever 63 and the associated eccentric shifting mechanism, so that the strength of the blow delivered by the toolk may be varied in accordance with the changing character of the coal or rock being worked.

vWhat I claim is:

1. In a reciprocating tool mechanism, the combination with the tool cylinder and the piston therein, of a compressor comprising a cylinder and a piston, ducts leading from said compressor cylinder to the front and rear ends, respectively, of the tool cylinder,

and means controlling the passage of air' through said ducts timed to subject the front side of the tool piston to a relatively low effective pressure throughout one stroke of the compressor piston and the rear side of the tool piston to a relatively high eective pressure during a part only of a succeeding stroke of the compressor piston.

2. In a` reciprocating too-l mechanism, the combination with the tool cylinder and the piston therein, oi a compressor comprising a cylinder and a piston, ducts leading fromy said compressor cylinder to the front and rear ends, respectively, lof the tool cylinder, and positively actuated means controlling the passage ofk air through said ducts ,compressor piston.

8. In a reciprocating tool mechanism, the combination with the tool cylinder and the piston therein, of a compressor comprising a cylinder and a piston, ducts leading from said compressor cylinder to the front and rear ends, respectively, of the tool cylinder, and positively actuated means controlling the passage of air through said ducts to subject the front side of the tool piston to a relatively loiv effective pressure during one stroke of the compressor piston and the rear side of the tool piston to a relatively high effective pressure in a succeeding stroke of the compressor piston. i

e. In a reciprocating tool mechanism, the combination with the tool cylinder and the tool piston therein, or an air compressor comprising a cylinder and a piston, ducts leading ifi-om said compressor cylinder to the front and rear ends, respectively, of the tool cylinder, one of the ducts being open to conduct air from the compressor cylindery to one end ot' the tool cylinder during an entire stroke of the compressor piston, means for closing said duct during the iirst part or the succeeding stroke of the compressor piston, and means for closing the other duct to prevent passage of air from the compresy son cylinder to the other end of the tool cylinder during the first part of said succeeding stroke of the said compressor piston, c

5. In a reciprocating tool mechanism, the combination with the tool cylinder and the piston therein, or' a double acting compressor comprising a cylinder and piston, ducts leading from the respective chambers or' said compressor cylinder to the front and rear ends, respectively, of the toolr cylinder, means controlling the passage of air through said ducts to subject the :trent side oi' the tool piston to a relatively low e'ective pressure during one stroke of the compressor piston and the rear side of the said `tool piston' to a relatively high effective pressure in a succeeding stroke of the compressor piston, and means comprising a duct operative 1n at least one position vof the compressor piston Afor placing the tivol chambers of the compressor cylinder in communication with each other when said `chambers are in coinmunication with the front and rear ends, re-

spectively, of the tool cylinder.

6. In a reciprocating tool mechanism, the

ich i combination with the tool cylinder and the piston therein, of a double acting compressor comprising a cylinder and a piston, ducts leading from the respective chambers of said compressor cylinder to the front and rear ends, respectively, of the tool cylinder, means controlling the passageo't air through said ducts to subject the :trent side of the tool c succeedingstrolre of the compressor piston,

and means comprising a duct operative when the .compressorpiston is in one of its eX- L treme. ositions for alacino' the tivo chamyinder. y v v n f 7. Iny al reciprocating tool mechanism, the combination with the tool cylinder and a bers ofthe compressor cylinder'in communication with each other when said chambersl are in communication with the front and rear-ends, respectively, of the tool cylpiston therein, of a double acting compressor comprising a cylinder and aV piston, vducts leading fromthe respective chambers of said compressor cylinder to the front and rear ends, respectively, oi the tool cylinder, means @ntrolling the passage of air through said ducts to subject the front side of the tool piston to a relatively low effective pressure during one stroke of the compressor piston and the rear side-oi the said tool piston to a relatively high eil'iective pressure in a succeeding stroke of the compressor piston, and means lcomprising` a duct koperative when the compressor piston isl in each of its eX- treme positions for placingthe tivo chambers of' the compressor in communication with each other when said chambers are in communication -with the front and rear ends,

respectively, ofthe tool cylinder.

8. ln a reciprocating tool mechanisnnthe combination With the Atool cylinder and the piston therein, of a double acting compressor comprising a cylinder and a piston, ducts leading from the respective chambers of said compressor. cylinder to the front and rear ends, respectively, of the tool cylinder, means controlling the passage of air through said yducts to subject the iront side of the tool piston to a ielatiif'ely low elfective pressure during one stroke of the compressor piston and the-rear sidepgf tliesaidjool piston to a relatively high effective pressre a succeeding strokey of the compressor piston, and means comprisingv a duct operative in atleast one position of the compressor piston for placing the two chambers of the. compressor cylinder in communicaltion with each other.

9.l In a reciprocating tool mechanism, the combinationwith the toolcylinder, andthe tool piston therein, of an air compressor comprising a cylinder and a piston, chiots connecting the air compressorcylinder With the tool cylinder, means for opening and closing the said ducts,^and Va duct supplemental to the aforesaid ducts for conducting air from the front end of the compressorcylinder to the rear end thereof when the vcompressor piston is at the end of its oroi the compressing piston and closed duringV the first part of the rearward stroke thereof, and means lto maintain the duct communicating With the rear end of the tool cylinder closed during the iirst part of the rearward stroke of the compressor piston.

1l. In a reciprocating tool mechanism, the combination with the tool. cylinder and the tool piston therein, of a double acting compressor comprising a cylinder anda piston, ducts leading from the respective chambers of said compressor cylinder to the front and rear ends, respectively, ot the tool cylinder, means" for opening and closing the said ducts at predetermined points in the movement of the compressor piston, means comprising a duct automatically operative inA at least one position of the compressor piston for placing the tivo chambers of the compressor in communication With'each other, and automatically acting means for admitting air tromv the external atmosphere to one of the compressor chambers.

l2. ln a reciprocatingtool mechanism, the combination with the tool cylinder and the tool piston therein, of the air ycompressing cylinder, a piston therein, the ducts leading from the compressor to the front vand rear ends, respectively, ot' the tool cylinder, the valves for opening and closing said ducts, the powerA shaft operatively connected to both the compressor piston and the valves, and means for varying thetime of opening oi' said valves.

'13. ln a reciprocating tool mechanism, the vcombination with the tool cylinder `and the tool piston therein, of the air compressing cylinder, piston therein, the ducts leading from the compressor' cylinder to the front and rearv ends, respectively, oil the tooll cylinder, the valves for opening and closing said ducts, the poive 1 shaft operatively connected to both the compressor piston and the valves, and means for varying the time of opening of said valves without varying the time of their closing.

iio

la. ln a reciprocating tool mechanism, they combination of the tool cylinder and the tool piston therein, o'l the air compressing cylinder, a piston therein, ducts leading from the compressor cylinder to the front and rear ends, respectively, Volf the tool cylinder, a valve mechanism tor opening and closing the aforesaid ducts, a power shaft operatively connected to the compressor piston and the said valve mechanism, and means for varying the time at which the valve mechanism opens the said ducts.

15. ln a reciprocating tool mechanism, the combination With the tool cylinder and the tool piston therein, ci the air compressing cylinder', the piston therein, ducts leading from the compressor cylinder to the front and rear ends, respectively, or the tool cylinder, the valve mechanism for opening and closing the aforesaid ducts, the power shaft operatively connected to both the compressor piston and the valve mechanism, and means for varying the time at Which the valve mechanism opens said ducts Without varying the time at Which it closes the saine.

lo. ln a reciprocating toolmechanism, the combination with the tool cylinder and the tool piston therein, of an air compressor comprising a cylinder and a piston, ducts leading from said compressor cylinder to the front and rear ends, respectively, of the tool cylinder, one of the ducts being open to conduct air 'from the compressor cyliii der to one end of the tool cylinder during an entire stroke of the compressor piston, means for opening and closing the last said duct and means controlling the passage oiE air through the other duct to canse the admission or' air at a relatively high pressure to the other end of the tool cylinder during the part only of a succeeding stroke of the compressor piston, and means comprising a duct operative in at least one position olf the compressor piston ttor placing the tivo chambers of the compressor cylinder in communication With each other when said chambers are in communication with the front and rear ends, respectively, or the tool cylinder.

17. ln a reciprocating tool mechanism, the combination of the tool cylinder, the piston therein, the front air port 12 remote 'from the front end oi' the cylinder, the rear air port 13 closely adjacent to the rear head or the tool cylinder, the duct leading to the port 12 having its inlet port 1(3 axi'ally near the port 12, the duct 14 having its inlet port 15 relatively near the center or' the stroke of the tool piston, the valves 29 and 30, for the inlet ports 15 and 16 oli the said ducts,

Copies of this patent may be obtained for the valve chamber for said valves extending to the iront and to the rear of both of said inlet ports, means for actuating the valves,

and means acting in cooperation With the` valves to supply air under pressure to said inlet ports alternately, substantially as set forth.

18. ln a reciprocating tool mechanism, the combination or' the tool cylinder, the piston therein, the front port 12, the rearport 13, the valve mechanism coi trolling the said ports, the compressor piston, he compressor cylinder having ports communicating With the ports in the tool cylinder, and having at its ends respectively the by-pass ducts 25 and 28, with ports 23 and 27 respectively adjacent to the compressor cylinder heads, and ports 24e, 26 respectively near the center axially of the compressor cylinder', and means for actuating the compressor piston and the valve mechanism in timed relation so that the chambers of the tool cylinder are in communication with the chambers of the compressor cylinder when the latter are in communication with each other through one or the other of the said ley-pass ducts, substantially as set forth.

19. ln a reciprocatingtool mechanism, the

combination or' the tool cylinder, the pisl ton therein, the portsat the front and at der, the valve mechanism controlling the said ports, the valve chamber, the compressor cylinder haifing the port 17 for delivering air to the rear end of the tool cylinder, and the port 18 for delivering air tothe front end or the tool cylinder, and having the by-pass ports 23, @il and duct 25 at one end and the by-pass ports :26, 27 and the duct *28 at the other end, the valve 54 controlling commnnication with the external atmosphere, and means or actuating the compressor piston and in timed relation so that the chambers of the tool cylinder' are in communication With the chambers oi, the compressor cylinder When the latter are in communication With each other through one or the other of the said by-pass ducts, and so thatthe compressor cylinder chamber into which the valve 5a opens is closed at a time when said chamber is expanding with the movement of the compressor piston, substantially as set forth.

In testimony whereof I alix my signature, in presence oi tivo Witnesses.

l/VALTER l?. TROTTER.

`Witnessesz F. L. Siissioivs, C. E. VVAXBORN.

live cents each, by addressing the Commissioner of Eatents,

Washington, D. C.

the valve mechanism 

